MC Final: Muscles Mechanics and Neuromuscular Control Flashcards
What is order of human movement control?
movement plan- central and peripheral nervous system- musculoskeletal system- action
Which part of the muscle generates the force?
the muscle belly
Which part of the muscle represents the elasticity?
external tendon, the more compliant this is the faster a muscle can contract
What is happening during an isometric contraction?
even though the joint isn’t moving the muscle belly is shrinking and external tendon is stretching
What is absolute strength?
maximal isometric strength- related to number and size of muscle fibers- how much force generating material do you have
What is the link between strength and neural noise?
stronger you are the less neural noise you have, less neural excitation is needed to produce a given force
therefore weaker you are the noisier it is for example as you age harder to do stuff, co - activation can be used as well
What is the force length curve?
the longer the muscle fibers are the more force that can be produced
What is intrinsic stability?
if muscle is stretched by an external force than muscle becomes stronger without neural control due to spring like effect of tendon
What is the force velocity relationship?
the faster you move the less amount of crossing bridging between actin and myosin builds therefore less force is created
Why does force velocity eccentric movement create more strength?
instead of ATP dependent detachment, action myosin bonds are pulled apart resulting in more tissue damage
What is a pre flex?
springs can stabilize during a perturbation, example is the cockroach experiment- intrinsic stabilization
What is the equilibrium point control?
movements generated through a gradual transition of equilibrium points along a desired trajectory
What are implications of EPC?
nervous system would not need to directly estimate limb dynamics
muscles and spinal reflexes would provide all the necessary information about the system’s state
What is an advantage of springy muscles?
elastic energy storage, more efficient locomotion, may aid explosive movements
What happens to muscle properties with aging?
changes in force velocity- less power and cannot produce force quickly like recovering from a trip
increased stiffness- decreases velocity of a muscle fiber and tendons cannot take up slack
